[LeetCode]#832. Flipping an Image

Fatboy Slim
1 min readMay 1, 2020

Environment: Python 3.7

Key technique: XOR ^

Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image.

To flip an image horizontally means that each row of the image is reversed. For example, flipping [1, 1, 0] horizontally results in [0, 1, 1].

To invert an image means that each 0 is replaced by 1, and each 1 is replaced by 0. For example, inverting [0, 1, 1] results in [1, 0, 0].

Example 1:

Input: [[1,1,0],[1,0,1],[0,0,0]]
Output: [[1,0,0],[0,1,0],[1,1,1]]
Explanation: First reverse each row: [[0,1,1],[1,0,1],[0,0,0]].
Then, invert the image: [[1,0,0],[0,1,0],[1,1,1]]

Analysis:

  1. Reverse input matrix.
  2. Use XOR to get answer.

Solution:

class Solution:
def flipAndInvertImage(self, A):
x,y=len(A),len(A[0])
for i in range(x):
A[i] = A[i][::-1]
for j in range(y):
A[i][j] ^= 1
return A

Submissions:

Reference:

https://blog.csdn.net/fuxuemingzhu/article/details/80471495

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